Detailed Summary

The book continues shortly after the previous installment left off, skipping only Severian's journey from the gate of Nessus to the nearby town of Saltus. Having been separated from the rest of the group he was traveling with, Severian is now travelling with Jonas, the man he met at the gate. During the Saltus Fair, Severian describes the executions of two people. The first was found to be a servant of Vodalus, a revolutionary and traitor to the commonwealth. As the man is dragged out of his home by a mob, Severian glimpses Agia, a woman whose brother Severian had executed, in the crowd. Severian searches for her at the town fair but instead has a conversation with a man whose skin is green, held prisoner in a tent as a sideshow attraction. The green man tells Severian he is from the future. Severian takes pity on him and gives him half of his whetstone. He does not find Agia and instead returns to town for the second execution, that of Morwenna.

Eating dinner with Jonas that evening, he finds a letter purportedly from Thecla asking him to meet her at a nearby cave. Severian steals a destrier from the inn's stable. In the cave, Severian encounters and barely escapes a group of man-apes. He cuts off the hand of one of these creatures and when Severian brings out the Claw of the Conciliator, the wound is healed. Severian has little time to ponder this as he first escapes some unknown creature, only to be attacked by Agia and her assassins outside the cave. Severian lets Agia go and returns to Saltus, where he and Jonas are kidnapped by Vodalus' men.

Vodalus recalls that Severian saved his life and asks Severian to enter his service. Severian and Jonas attend a dinner with Vodalus where they consume the dead Thecla's flesh, which, when combined with the analeptic alzabo, allows Thecla's memories to live within Severian. Given the task to deliver a message to a servant in the House Absolute, the Autarch's seat of power, Severian and Jonas set off to the north. They are attacked by notules and barely escape. A nearby soldier patrolling the area is killed by the creatures but then revived by the claw.

They are then captured by guards of the House Absolute and thrown into "the antechamber", where prisoners have been kept for generations. Jonas is weakened during the night they spend there; to calm him Severian reads The Tale of the Student and His Son from the brown book. The pair escape the antechamber, which is now stalked by some unknown horror, using a pass phrase to open a secret door—Severian remembers the phrase using Thecla's memory within him. They happen upon Father Inire's Mirrors in the House Absolute, and Jonas uses them to depart. Severian is lost and eventually encounters the Autarch himself, to whom he swears service, upon being shown a portal to another universe.

Stumbling into the gardens of the House Absolute, Severian is reunited with Dorcas, Dr. Talos, and Baldanders, who are preparing to once again perform the play they put on in Nessus in the first book. Severian participates again, but the play is cut short as Baldanders flies into a rage and attacks the audience, revealing that cacogens are among them.

The band is scattered, but Severian finds them the next morning, heading north. Talos and Baldanders part ways with Severian and Dorcas at a crossroad, Severian heading toward Thrax and the giant and his physician headed toward Lake Diaturna. The Jolenta tries to have Talos take her with him, but he rejects her, and Severian is forced to take her. As they head north, Jolenta becomes ill. An old farmer tells them they must pass through an enigmatic stone city to get to Thrax. Upon arriving at the ruinous city, they meet two witches, who Severian recognizes from his apprenticeship, accompanied by Hildegrin. The older witch, the Cumaean, initiates a dream-like event in which ghostly dancers of the stone town's past, including Apu-Punchau fill the streets. The book ends with Dorcas and Severian emerging from a stupor in the stone town, with Jolenta dead and the witches and Hildegrin gone.

An appendix follows.

From Wikipedia